The chains of chain-driven vehicles such as motorcycles and bicycles should be periodically lubricated to reduce wear and enhance performance. Chain lube is typically sold in aerosol cans together with straw-like supply tubes connectable to the outlet port of the can. If the lubricant is sprayed directly from the can's outlet port, substantial overspray typically results, even if the user endeavors to direct the lubricant to the critical wear points of the chain, such as the end portions of the roller pins between the lateral link plates. Accordingly a significant percentage of the lubricant is dispersed into the air in the vicinity of the chain. Application of the lubricant to the critical wear points of the chain may be more easily controlled if the supply tube attachment is used, but it is a time consuming and painstaking task to lubricate an entire chain in this fashion.
Some spray head attachments adapted for delivering lubricant directly to the wear points of a drive chain are known in the prior art. U.S. Pat. No. 4,815,637, which issued to Nellis on Mar. 28, 1989, discloses a cap assembly for use with canned aerosol lubricant which is designed to direct a foam lubricant between the lateral link plates of a drive chain. The Nellis cap assembly includes a cap for engaging the upper end of a can of aerosol lubricant and an arm extending radially from the cap for delivering lubricant from the can's spray head to a distal outlet head. The distal outlet head has a recessed portion having a length slightly greater than the width of a drive chain to facilitate placement of the outlet overlying the chain. Lubricant from the aerosol can is expelled through a pair of holes formed in the outlet head directly onto the drive chain.
The Nellis design has various shortcomings which are overcome in the present invention. The Nellis outlet head is but one element of an overall cap assembly and is not intended to be used solely with supply tubes sold together with aerosol lubricants. The cap portion and radial arm of the Nellis invention can hinder placement of the outlet head on hard-to-reach portions of the drive chain. Further, the shape of the recess formed in the Nellis outlet head does not facilitate rapid travel of the head over the chain's rollers or prevent overspray onto the central portions of the rollers. Additionally, the formation of the boreholes drilled in the Nellis outlet head causes differential flow of lubricant through the outlet apertures, resulting in uneven application of the lubricant to the chain.
Accordingly, the need has arisen for a spray head connectable to the outlet port of an aerosol can which is specifically shaped to efficiently direct aerosol lubricant to the wear points of a drive chain.